@article{RM_1984_39_6_a0,
     author = {N. N. Bogolyubov (Jr.) and I. G. Brankov and V. A. Zagrebnov and A. M. Kurbatov and N. S. Tonchev},
     title = {Some classes of~exactly soluble models of~problems in~quantum statistical mechanics: the~method of~the~approximating {Hamiltonian}},
     journal = {Trudy Matematicheskogo Instituta imeni V.A. Steklova},
     pages = {1--50},
     publisher = {mathdoc},
     volume = {39},
     number = {6},
     year = {1984},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/RM_1984_39_6_a0/}
}